Looper mechanism for chain-stitch sewing machines



L OOPER MECHANISM FOR CHAIN STITCH SEWING MACHINES Filed May 8. 1924 2 Sheets-Sheet 1 {my w WM INVENTOR 553w M NES s v Bf/ I WIT g g 244.- ZM MM TTORNEY May 25 1926. 1,585,665

A. GRIEB LOOPER MECHANISM FOR CHAIN STITCH SEWING MACHINES Filed May 8, 19 2 Sheets Sheet 2 INVENTOR jfiw 62% j WKSSI? ,7 BY I 7 Patented May 25, 1926.

1,585,665 PATENT QFFHQEQ UNITED STATES ALFRED GBIEB, OF ELIZABETH, NEW JERSEY, ASSIGNOR TO THE SINGER MANUFAC- TURIN G COMPANY, OF ELIZABETH, NEW JERSEY, A CORPORATION OF NEW JERSEY.

LOOIPER MECHANISM FOR CHAIN-STITCH SEWING MACHINES.

Application filed May 8,

This invention relates to improvements in chain-stitch sewing machines and has for its primary object to provide an improved stitch-forming mechanism for producing a chain-stitch seam adjacent the margin or fold-margin of the work.

A further object of the invention is to provide a sewing machine of the horizontal needle hat-sewing type With improved stitch-forming mechanism effective to produce a chain-stitch seam having the needle thread loops enchained at one side of the work substantially in the line of seam-forination.

In its preferred form the present inven-' tien comprising an improved looper-mec'hanism, has been embodied in a hat-sewing machine of the horizontal-needle type wherein the work is primarily supported by a disk projecting between opposed feed and presser wheels rotatable upon substantially vertical axes. A hat-sewing machine of this type is disclosed in my prior Patent No. 1,206,433, issued Nov. 28, 1916. While the needle reciprocating mechanism may be of ordinary construction, its complemental looper cooperates therewith in a novel manner to enc'ha'in the needle-thread loops at one side of the Work in substantially the line of seam-formation. The looper-beak is confined to operative movements at one side of a vertical plane coincident with the line of feed at the stitching point, and its shank is supported upon the opposite side of said plane for pivotal movement about trans verse axes. The operative movements of the looper are derived from suitable cams upon the main or needle-actuating" shaft and are of a character .such that the loop'er-be'ak sue cessively performs an endwise advancing or loop-seizing movement; a lifting movement occurring while the needle is free of" the work primarily to facilitate insertion and removal of said Work; a loop-presenting movement, and a retracting or loop-shedding movement.

In the accompanying drawings, Fig. 1 is a side elevation, partly in section, of a horizontal-needle hat-sewing machine in which the present improvement has been embodied. Fig. 2 is a top plan view of the same machine, omitting the top cover-plate. Figs. 3 to 7 inclusive are perspective views ilhlstrating the cooperation of the needle and looper in the formation of a blindchain- 1924. serial No. 711,757.

stitch seam. Fig. 8 is a plan view and Fig. 9' a sectional view of a product of the machine.

Referring to the drawings, the present improvement is shown as embodied in a sewing machine having a base 1, a bed-plate 2 and an upright standard 3 closed by a hinged cover-plate 4. Rising from the bed-plate 2 is a vertical shaft 5 carrying at its upper end the horizontally disposed feed-wheel 6 which receives intermittent feeding move ments from a feed-lever 7 vibrated as usual from the mainshaft 8. The main-shaft 8 is journaled for rotation in bearings provided in the stai'idard 3 and may be rotated in any suitable manner. Yieldingly' opposed to the feed-wheel 6 is a presser-wheel 9 mounted upon the depending portion 10 of the presserarm 11, which rises from below the bedp'lateof the machine and is, as usual, under the action of a spring 12. The pres'ser-wheel 9 may be retracted from its operative position by actuation of a lever 13 suitably connected with a treadle (not shown), for the purpose of insertion and removal of work. Projecting between the feed-wheel 6 and the pr'e.sser-vvheel 9 is the beveled periphery of a work-supporting disk 14: having a balljoint support upon the disk-carrying lever 15 adjustably fulcri'imed upon the presserarm 11 and yieldingly maintained in its operative osition by the action of a spring 16 Mounted for horizontal reciprocation in suitable bearings provided in the standard 3 is the needle-bar 17 provided with the needle-clamp 18 in which is secured the needle 19. The needle-bar is reciprocated by an eccentric 20 upon the main-shaft 8, which eccentric is straddled by a fork 2'1 depending from the needle-bar. Cooperating with the needle is a looper 22 having an operative loop-seizing beak 23 terminating at one side in a depending loop-detaining spur 24. The looper-beak 23 is confined to operative movements at one side of a vertical plane coincident with the line of feed at the stitching point but is sustained on the opposite side of said plane for movement about substantially transverse axes. To this end, the lo'oper-shank is secured, by screws 25, Within the lateral boss 26 of a sleeve 27 mounted for pivotal movement about a fulcrum-pin 28 The fulcrum-pin 28 has a hub 29 secured by means of a set-screw 30 upon a rock-shaft 31, substantially parallel with the main-shaft 8 and j ournaled in suit able bearings provided in the standard 3. The flattened upper surface 32 of the hub 29 afi'ords a seat for the sleeve 27, endwise movement of the sleeve upon its fulcrun'i-pin being prevented by means of a collar 33 suitably clamped upon said fulcrum-pin.

Projecting laterally from the sleeve 27, on the side opposite to the boss 26, is an actuating arm as carrying at its free end a de pending roller 35 entering a peripheral camgroove 36 formed in a cam 37 suitably secured upon the main-shaft S. The cam 37 is also provided with a face cam-groove 38 entered by a roller 39 carried by the free end of an arm l0 having a split hub l1 clamped by means of a screw 42 upon the rock-shaft 31.

Preferably an overlying guide 4L3 is opposed to the disk 14:, the shank 4A of this guide being disposed at the side of the needle occupied by the looper-beak when retracted, whereby clearance is provided for the looper-beak to occupy its loop-presenting position. The guide-shank 44 is shown as adjustably secured upon the usual needleguide blocl; 45 by means of as crew 46.

It is evident that upon rotation of the main-shaft 8, the canrgroove 86 will actuate the arm 34. to cause oscillatory movements of the looper upon the fulcrum-pin 28, whereby the looper-beak 23 is caused to ad Vance to seize a loop of thread presented by the needle and to shed this loop durin its retracting movement. Rising and fa ling movements are imparted to the looper, about an axis substantially transverse to the fulcrum-pin 28, from the cam-groove 38. The looper-beak reaches its raised position while the needle is in its retracted position, i. e., when the needle is free of the work, whereby to insure greater freedom for insertion and removal of work as well as to insure that the looper will not interfere with retraction of the presser-wheel 9 for the same purpose. Incidentally, the rising movement of the looper in conjunction with the feeding movement of the work serves to set the preceding stitch. The descending movement of the looper-beak constitutes a loop-presenting movement, i. e., a movement to present the loop of thread held by the looper for entrance by the needle.

Referring now more particularly to Figs. 3 to 7 inclusive, it will be observed that in the seam s the needle-thread loops are enchained at one side of the work w in the line of seam-formation. In Fig. 3 the needle has entered a loop previously presented by the looper and has just commenced its retracting movement, while the loo oer-beak 23 is about to advance to seize the oop a presented by the needle. In Fig. 4 the needle is about to withdraw from the work and the Lasaace loop a has been seized and is now held by the advancing and partially rising looperbeak 23, the loop being detained on said beak by the depending spur 2a. In Fig. 5 the needle has emerged from the work, the

looper-beak has reached its highest point and the feed of the work has commenced, thereby setting the preceding stitch. In this position of the parts, the pressenwheel may be readily retracted by manipulation of the lever 18 and the work inserted or removed from the machine. I he looper-beak now descends to its lowest position as indicated in Fig. 6 to spread the loop a for entrance by the now advancing needle. The looper-beak thereupon partially rises and sheds the loop a during its retracting movement into initial position, as indicated in Fig. 7.

lVhile the present stitch-forming mechanisin may be employed for obtaining various products, it is particularly adaptable for hat-sewing work. The work w, shown in the drawings, constitutes for instance the brim of a hat,'the margin of which has been edge-folded and doubled over the periphery of the work-supporting disk 14%. By a proper adjustment of the height of the disk 14:, the needle may be caused to secure the edge-fold by blindstitching, as illustrated more particularly in Figs. 8 and 9. In the finished product, the thread does not show on the under side of the hat-brim and the enchained loops underlie the folded margin of the work 20, the latter being due to the formation of the enchained loops closely adjacent to the work-margin while the work is bent over the disk l-fl. Upon subsequent straightening out of the hat-brim, the folded-margin is caused to overlap the enchained loops of the seam.

Having thus set forth the nature of the invention, what I claim herein is 1. In a chain-stitch sewing machine, the combination with a thread-carrying needle disposed in substantially a horizontal plane, means for reciprocating said needle, a workfeeding wheel rotatable upon a substantially vertical axis, means for rotating said feedwheel, and a presser opposed to said feedwheel, of a looper cooperating with said needle to enchain needle-thread loops in the line of seam-formation on the presser side of the work, supporting means for said looper disposed on the opposite side of the work, and means for actuating said looper.

2.In a chain-stitch sewing machine, in combination, a thread-carrying needle disposed in substantially a horizontal plane, means for reciprocating said needle, a feedwheel disposed to rotate upon a substantially vertical axis, means for rotating said feedwheel, a workpresser yieldingly opposed to said feed-wheel, manually controlled means for retracting said presser to permit insertion and removal of the work, a looper cooperating with said needle having a threadengaging beak confined in its operative movements to the work presser side of the work, supporting means for said looper disposed on the opposite side of the work, and means for actuating said looper.

8. In a chain-stitch sewing machine, in combination, a thread-carrying needle, means for reciprocating said needle in a substantially horizontal plane, work-feeding means, a looper having a loop-seizing beak coope 'ating with said needle to enchain needle-thread loops at one side of the work in the line of seam-formation, and actuating means imparting to said looper-beak an endwise loop-seizing movement past one side of the needle, a sidewise stitch-setting movement upwardly away from said needle above said horizontal plane, a loop-presenting movement, and a loop-shedding movement, the loop-seizing and shedding movements terminating on the same side of a plane transverse to the needle and coincident with the line o1 feed at the stitching point.

4. In a chain-stitch sewing machine, in combination, a horizontally reciprocating needle, means for reciprocating said needle,

work-feeding means, a looper having a loopselzlng beak cooperating with said needle to enchain needle-thread loops at one side of the work in the line of seam-formation, and means for actuating said looper-beak in substantially transverse directions, including a substantially horizontal loop-seizing movement above the needle-path of movement, and a loop-lifting movement upwardly away from said needle.

5. In a chain-stitch sewing machine, in I combination, a horizontally reciprocatory thread-carrying needle, means for reciprocating said needle, opposed work-feeding and presser-wheels, a work-supporting member having awork-engaging edge disposed in a plane intermediate said wheels, a work-guide opposed to said member, a looper cooperating with said needle and having a beak confined to operative movements at one side of said plane, and supporting and actuating mechanism for said looper disposed upon the opposite side of said plane.

In testimony whereof, I have signed my name to this specification.

ALFRED GRIEB. 

